Cooling system for diesel engines



Jan. 8, 1946. E. F. CHANDLER 2,392,723 I COOLING SYSTEM FOR DIESEL ENGINES Filed March 15, 1945 2 Sheets-Sheet l IN VEN TOR.

Jan 8, 1946.

E. F. CHANDLER COOLING SYSTEM FOR D IESEL ENGINES Filed March 15, 1945 2 Shees-Sheet 2 INVENTOR.

Patented Jan. 8, 1946 UNITED -s'r 're Edward. F. Chandler, Brooklyn, N. Y. Application March 15, 1945, Serial N 582,848 9 Claims. (c1. m rvel This invention relates to cooling systems for Diesel and other internal combustion engines, and

has for itsprincipal object the provision of an improved system for controlling the temperature of the lubricating oil thereof, and also for controlling the temperature of the engine cooling water. The present application constitutes a. continuetion-iu-part of my ctr-pending application Serial No. 575,498,1flled January 31, 1945.

The use of heeteizchangers in connection with marine installations of internal combustion engiues has become practically universal. A com moo arrangement for Diesel engine cooling sys tems provides two heat exchangers; one for coollog the engine iecket water, and the other for cooling the engine lubricating oil. See, water is circuleted through these heat exchangers as the coolant, the usual arrangement providing for series flow oi the sea water, first. through the lubricating oil heat exchanger and thence through the jacket water cooler.

A somewhat less common engine cooling sys-= tern provides for cooling the engine locket water, as described above, but instead of circulating sea water through the lubricating oil cooler, the

cooled jacket water is employed as the coolin medium, This type of cooling system has the advantage of exposing only one of the two heat exchangers or coolers to the corrosive action oi? sea water, and the further advantage that, upon starting a cold. engine, the engine and the Cine failure, decreased reliability, and excessive maintenance and repair requirements. This is particularly true in thecase of high-speed Diesel er tries, and it has been definitely established that engine deterioration is very rapid whenever operation proceeds with either lubricating oil or jacket water circulating eta temperature below 130 F, c

The principal object of the present invention is to avoid the culties encountered by the use of see, weter circulating through the lubricating oil cooler, and to take maximum advantage of cir-.

culatlng jacket water through such cooler for rapid heating of the chilled lubricating oil upon starting cold engines, and, inaddition, to provide for automatic control of the temperatures of the lubricating oil end jacket water within the optimum. operating rouge, as specified by the engine designer, regardless of variations in the power at which the engine is operated, or variations in the temperature or the sea. water.

lubricating oil end the Jacket water temperatures are elevated to the proper operating tempera, ture rouge much more rapidly than when the colder sea water is circulated through the lubricetlug oil cooler. This type of cooling system has the disadvantage of requiring the use of somewhat larger hoot exchangers for a given instsl= latiou, which, to some extent, offsets the advan tages derived therefrom.

However, the advantage obtained by circulatlug jacket water through the lubricating oil cooler,

become extremely important in view of current operations of Diesel engine propelled navel vessels in the northern and southern cold sea areas. Reports show that, in many cases, the chilled engine lubricating oil in vessels operating in these areas, and not equippedfor jacket water circulation through the lubricating oil coolers, never reaches the proper operating temperature even after hours of engine operation, resulting iu with these and other objects in View, as well as other advantages that may be incident to the use of the improvements, the invention consists in the parts and combination thereof hereinafter set forth and claimed, with the understanding thatthe severei necessary elements'constituting the samemay be varied in proportion and arrangement without departing from the nature and scopehf the invention, as defined in the appended claims 7 In order to make the invention more clearly understood, there are shown in the accompanylug drawings moons for carrying the invention into practical use, without limiting the improvements in their useful application to the particuler construction, which, for the purpose of ex plesietion, has been made the subject of the illustretious.

Fig. l. of the accompanying drawings isms. diaerammutic view of a system of automatically controlling the temperature of the lubricating oil and locket water of an internal combustion engine wherein the jacket Water, by a simple and improved method, is employed-to'control the temperature of the lubricetingoil; and

Fig; 2 is a diagrammatic View of the valves,

thermal responsivc elements and electrical circuits, and means for the automatic operation of the system, all of the same being schematically presented tor the purpose of illustrating the inventive idea. i

Like numerals in both figures of the drawings refer to similar parts.

acceieratedwear of allbearing surfaces, early en-. 68 .Referrmg to the drawings, a system for controlling the temperature of the lubricating oil and Jacket water or an internal combustion encooler 3. The Jacket water cooler 2 is provided with a heat-transfer element 4 through which I gine is shown as comprising, generally, an engine I 'sea water, or other fluid coolant, is circulated I from pipe 5 and valve 6, and from which the 1 coolant escapes through pipe I. This cooler is also provided with a heat-transfer element 8, through which jacket, water to be'cooled is supplied from the engine. The cooled jacket water escapes from the heat-transfer element 8 through pipe I8, in'wh'ich is positioned a suitable valve 26 by means of which the jacket water escaping through pipe l8 may be automatically caused to flow through pipe I! or pipe25, on its return to the engine I, as more fully described hereinafter.

In the pipe it, through which the jacket water 1 leaves the engine, is positioned a thermally-responsive switch element 23 and a suitable valve :21, by means or'which water flowing from the engine, through pipe l5, may be directed through pipe is or through pipe 23, as hereinafter described. The pipe 23 is adapted to deliver. jacket water from the engine to the heat-transfer eleor to pipe 23, or to both. Accordingly, all or a portion of the heatedjacket water may be de-" livered to the cooler 2, or all Or a portion thereofmay be, passed through the cooler 3, as may be required. The water leaving the cooler 2, by pipe 13, delivered to the two-way, automaticallycontrolled'valve 26, may be directed back to the engine through pipe1l9, or all or a portion thereof may be shunted through pipe 26 into pipe 23, so as to pass the same'through element i1 0! thecooler 3 before'it is delivered by pipe to the.

return pipe IS, in which case valve 21 would be positioned-to close the valve-port governing fluid flow in the limb 23' of pipe 23.

For simplicity and clearness, temperature and pressure-indicating means, and other auxiliary equipment common to systems of this order, have not been shown in the drawings. Also, reference should be made to -my co-pending application previously referred to, as features and means disclosed in both applications may be combined" and coordinated to produce a desired end result.

Valve 6, which may be manually or-automatically controlled, serves to govern the quantity of sea water or other coolant passing through the initially starting the engine, and with the engine in operation, the jacket water is rapidly heated, and this heated water directly enters the heat exchanger 3, providing for rapid heating of the cold lubricating oil circulating through the oil heat exchanger element 2|. In this connection, it will be understood that in most types of internal combustion .engines, the amount of heat dissipated into the jacket water by the operation of the engine is about ten times the amount of heat dissipated into the lubricating oil. Therefore, the jacketwater is heating very 'much more rapidly than the lubricating oil upon starting'a cold engine, because, in this present system, the principal jacket water cooling is governed by heat exchanger 2. In the preferred method of operating this system, as the jacket water temperature becomes elevated to the operating range, the temperature of the heated water being returned to the engine through the pipe I9 is gradually reduced by blending therewith some jacket water which has been cooled by having been passed through cooler 2. From cooler 2 said cooled water carried by pipe I8 is directed by valve 26 into pipe l9, wherein it is mixed with'water leaving the heat exchanger 3, through pipe 24, the cooler admixture then being returned to the engine.

The positioning of the valves 26 and 21 to selectively direct the flowing streams of jacket water to bring about a desired modification of the temperature of the water being returned to that upon starting a .cold engine, the tempera- 1 ture of the lubricating oil can be rapidly raised to the desired optimum operating temperature and maintained substantially at the 'optimum temperature during the continued operation of the engine. vAlso, by these means, when the lubricating oil is at the optimum temperature, sufllcient jacket water is forced through the cooler 2 to maintain a constant predetermined temperature of the jacket water regardless of the temperature of the sea water circulating through the jacket water cooler, and regardless of variations in the power being generated by th engine.

With a substantially constant temperature ,maintained in the jacket water leaving the .en-

, gine through the operation of the automaticallyelement 4 in the cooler 2. If desired, the same;

purpose may be served by the provision of a circulating water by-pass around this cooler. Lubricating oilfrom the engine may als be bypassed around the lubricating oil heat exchanger and directly back to the engine through the bypass pipe .I23, and an automatic, spring-loaded,-

pressure-relief valve 124, when the engine is ini tially started. The by-pass pipe 23 can be ar- In operation of this improved system, upon governed valves 26 and 21, causing more or less heat to be released by the heated jacket water, it will be noted that at any given engine power, the temperature of the jacket water and lubricating oil circulated to and from the engine remains substantially constant, regardless of all changes in the temperature or quantity of the sea water circulated through jacket water cooler 2. This'is apparent by reference to the drawings. At con stant engine power, heat dissipated to and from the oil and jacket water in the engine and the heat exchangers or coolers is substantially constant. Therefore, with a constant engine jacket water discharge temperature, the temperature of the jacket water entering the engine is substantially constant, because the rise in tempera- 3 nection 22' passes before issuing irom. the pipe connection 22.

stant, the temperature rise of the jacket water and lubricating oil to and from the lubricating oil heat exchanger remains constant.

Thus, regardless of changes in the temperature and quantity of the sea water, the oil and the jacket water temperatures to and from the.

engine are maintained substantially constant at any' given engine power, which is a very'desirable engine operating condition from the standpoint of engine service life and reliability. By properly' proportioning .the size of the heat exchangers, and by suitably adjusting the automatic control means, it is possible to providefor cooling the lubricating oil flowing to the engine to a temperature as low, or even lower, than the temperature of the jacket water flowing to the engine. Also, the system renders possible a minimum temperature rise of the jacket water flowing through the engine, which is very desirable for certain types of engine installations.

Referring to Fig. 2, 26 and 21 represent, schematically, valves of any type suitable for the purpose described. Valve 26 is providedwith a piston comprising members 35 and 36 which are fitted to, and adapted to-slide within, the valve bore 31, said two members being carried bythe operating rod 38. Fluid enters the valve bore through pipe I8, and when the piston is in the position shown, is free to issue from the valve through 'pipe IS, the outlet port to pipe 25 being 1 closed by the piston member 36. The valve operating rod 38 is provided with an armature 39 positioned axially within the two solenoid coils and 4|, by means of which the valve is selecl9 and thus permitting fluid to flow through pipe [6, into the valve bore, and out through-pipe. -25. When the coils 40 and 4| are de-energized,-the armature is caused to assume this extreme posi- Positioned within the chamber 25, and in contact'withsaid fluid, isa heat-responsiveelement 56 having a'rod 51 which carries the contact plate 58, having an insulated portion 59. The element 56, by means of the rod 51, is adapted to move the plate 58 axially, forward and back, depending upon the temperature of the fluid being circulated through the chamber 55. Contact fingers 60, 6|, 62, 63 and 64 are adapted to complete circuits through plate 58 to operate valves 26 and 21 in a predetermined manner, in response to the temperature of said fluid circulating through chamber 55.

Conductor 10 connects contact finger 64 with conductor H of the power source. Conductor 12 connects conductor 13 of the power source with contact finger 15 of the thermally-actuated switch 28.. Contact finger 1601 said switch is connected by conductor H with conductor 18,

which is connected at 86 with the coils 41 and 48, and y conductor 19 which is connected at 8| with the coils 40 and '41. tween the fingers l5 and 16 of the switch 28 is completed by the conducting member 90 carried by the rod 9|, by means of which the member is moved axially into and out of contact with the fingers 15 and 16 in response to temperature changes of the fluid circulated through pipes i5 andd [5' in contact with the heat-sensitive aotuating means. The thermal switch member 26 is indicated as positioned in pipe l5 through which jacket water from the engine issues.. In this instance, the switch would be so adjusted Electrical contact be-.

that the electric circuit between the fingers 15 I and 16 would be open, and would remain open by the retraction of the contact member 90 from between saidfingers, until the jacket water leaving the engine has been heated to a predetermined'temperature. When said predetermined temperature has been attained, due to the thertion to the right by the spring 42,- which, as I shown, may be positioned upon rod 38 between the wall 43 and the inner face of the armature 33. Valve 21 is similar to valve 26 in all essential details. v

Fitted within the bore 42 ofvalve 2'! is a piston comprising members 43 and 44 carried by the operating rod 45. In the valve setting shown, fiuid' enters the bore 42 through pipe l5 and issues through pipes l6 and 23". The armature 46 carried by the rod 45 is shownas midway between the two solenoid coils 41 and 48, indicating that both aresimilarly electrically energized. When .both coils are de-energized, spring. 49 acts to move the armature to its normal extreme left or outward position, in which case the outlet port to pipe I6 is closed by the member 44, and fluid entering the valve through pipe i5 will issue through pipe 23'. Preferably, both of the valves 26 and=21 are controlled by a single, thermallyactuated means 29 having a suitable chamber through which fluid delivered by the Pipe con- 74 trol system in readinesstoiunction, Likewise, the

mal response of the device, rod 9| is moved outwardly, bringing the member in contact with said fingers I5 and 16 to complete the circuit between .conductors l2 and 11. Accordingly, while the engine is idle and cold, the circuit is open between the fingers 15 and I6, de-energizing the entire electric control system.

Under the influence of the springs 42 and 49, both of the valves 26 and 21, when the solenoid coils 40, 4|, 4! and 48 are deenergized, assume their extreme outward positions. Accordingly, it will be noted that upon starting a cold engine, and until the jacket water has become heated sufflciently to cause thermally-actuated switch de-' time, the lubricating oil is being circulated from the engine by pipe 26, through the heat-transfer the thermally-actuated valve control device 29.

.element 2| of the cooler 3, and back to the engine through pipe 22, in which latter pipe is positioned The rapidly-heating jacket water quickly raises the temperature of .the lubricating oil. The

jacket water relatively soon will'reach the prede-' termined temperature for which switch unit 28 has been'set to closethe contact between the fingers-15 and 16, thereby placingthe valve contemperature of the lubricating oil will be increasing. v

Therefore, when the automatic valve control system takes over, the position of the thermallyactuated contact member 58 of the device 29 is preferably such that solenoid coil 40 of the valve 26, anclv both solenoid coils 4'! and 48 of the valve 2'1, are energized. In this manner, valve 21 may be selectively positioned to cause some of the heated jacket water to by-pass the cooler 3, and by means of pipe 16 to be delivered to theheattransfer element 8 of the jacket water cooler 2,

and then by Pipe H! to pass through valve 26 topipe l9, therein'to blend with the jacket water leaving the cooler 3, through pipe 24, and then back to the engine. In this manner, the quantity of water passing through either or both of the heat exchangers 2 and 3 may be controlled for the purpose of modifying the temperature of either or both the jacket water and the lubricating oil. 1

Should the temperature of the lubricating oil tend to increase above the desired optimum operating temperature, the increased heat of the oil being circulated through the engine will further actuate the thermally-responsive valve control means 29 to so position the contact member 58 as to cause the energization of the solenoid coils 46 of valve 26 and 4 1 of valve 21. This will cause a selective positioning of the valves whereby all of the jacket water leaving the engine through pipe [5 will pass through valve 21 to pipe I6 for delivery through the heat-transfer-element 8 of the cooler 2, then through valve 26 to pipe 25 for delivery by pipe 23 (the valve port to 23' being. closed by valve 21) to the heat-transfer element ll of the cooler 3, and then by pipes 24 and IS (the valve port to pipe section l9 being closed by valve 26) back to the engine It i to be understood that valves of any suitable design may be employed, and that the confthe engine, for the purpose of reducing the amount of oil cooling effect and/or for decreasing a the temperature of the engine jacket water.

From the foregoing, it will be apparent that a very efilcient system is provided for controlling the temperature of both the cooling water and the lubricating oil of the engine, by means of which the service life of internal combustion ennes is improved, and .the necessity for maintenance and repair decreased. Also, the improved Y system insures the rapid heating of chilled lubricating oil upon starting a cold engine, and the rapid warming up of a cold engine upon starting.

The temperature of the jacket water and lubricating oil is controlled entirely automatically.

The lubricating oil heat exchanger is not sub-' jected to the corrosive action of sea water. The

improved system'permits of simplified piping artrol or selective positioning of the valves employed may be by any suitable thermally-actuated means adapted for the purpose of carrying out the in- 1 ventive idea herein set forth. Also, as previously pointed out, the system shown in Fig. 2 of the drawings is purely schematic to diagrammatically illustrates working embodiment of certain features of the invention. U Broadly, the invention provide an improve jacket water cooler and an oil cooler are employed, and in which, when initiallystarting, a cold englneand in order to rapidly bring the lubricating oil up to the desired temperature, all of the jacket. water from the engine maybe passed through the lubricating oil cooler to transfer its heat thereto;

- (2). in which either the jacket water temperature or the oil temperature, or both, may be modified by controlling the flow of jacket water circulated simultaneously through both the jacket water cooler and the lubricating oil cooler, whereby the temperature of the jacket water may be reduced and/or less heat be transferred to the oil; (3) in which, when required, the jacket water may be passed first through the jacket water cooler and then through the lubricating oil cooler before 'being returned to the engine, as; for example, to increase the degree of lubricating oil cooling; and

(4) in which, when jacket water leaving the englue is passed first through the jacket water cooler and then through the lubricating oilcooler, some of-the'cooled water from the jacket water cooler may be by-passed around the oil cooler and directly mixed with the water being returned to rangement and the control of the temperatures of both the jacket water and lubricating-oil by simple, automatic governing means. The system has the additional advantage of providing for relatively small temperature rise of jacket water circulated through the engine with minimum size of lubricating oil heat exchangers.

.It will be understood that, whereas the above description of the present engine cooling system is particularly adaptable to marine engine installations, it is equally applicable to all other internal engine installationsi' For land installations. the term seawater, as employed herein, may

.be more properly termed cooling water? or a cooling fluid obtained from an external source, and for aircraft installations the primary cooling medium'may be air. v

' It will be understood, as'previously stated, that the above description and accompanying draw- I ings, comprehend only the general and preferred embodiment of the invention, and that various changes in construction, proportion and arrangement of the parts may be made within the scope of the appended claims without sacrificing any of the advantages of the invention.

What I claim is: I

1. A system for controlling the temperature of the cooling water and of the lubricating oil of an internal combustion engine, including a first heat exchanger for governing the temperature of, the

i system of the kind described (1) in which a engine lubricating oil, a second heat exchanger for cooling the engine jacket water, means for circulating lubricating oil from the engine through the first said heat exchanger, means for circulating jacket water from the engine through both of said heat exchangers simultaneously, and means for controlling the quantity of water circulated through the first said heat exchanger for both of said heat exchangerssimultaneously, and

means govemedby the temperature of the circulating lubricating oil controlling the quantity of water circulated through each of said heat exchangers.

3. A system for controlling the temperature of the cooling water and of the lubricating oil of an internal combustion engine, including a first heat exchanger for gcver the temperature of the engine lubricating oil, a second heat exchanger for cooling the engine jacket water, means for circulating lubricating oil from the engine through the first said heat exchanger, means for circulating jacket water from the engine through both of said heat exchangers simultaneously, and means whereby water circulated through the second said heat exchanger may subsequently be passed through the first said heat exchanger for governing the temperature of the lubricating oil.

4. A system for controlling the temperature of the cooling water and of the lubricating oil of an internal combustion engine, including a first heat exchanger for governing the temperature of the engine lubricating oil, a second heat exchanger for cooling the engine jacket water, means for circulating lubricating oil from the engine through the first said heat exchanger, means for circulating jacket water from the en ine through both of said heat exchangers simultaneously, and means governed by the temperature of the circulating jacket water for passing all of the engine jacket Water through the first said heat exchanger. f

5. A system for controlling the temperature of the cooling water and of the lubricating oil of an internal combustion engine, including a first heat exchanger for governing the temperature of the engine lubricating oil, a second heat exchanger for cooling the engine jacket water, means for circulating lubricating I oil from the engine through the first said heat exchanger, means for circulating jacket water, from the engine through both of said heat exchangers simultaneously, and means whereby water circulated through the second said heat exchanger may be' circulated greater cooling in two separate heat exchanger zones, subjecting a circulating stream of lubricating oil in indirect heat exchange relationship to the water circulating through the zone of lesser cooling, and returning to the engine, jacket water from either or both of said zones, depending upon whether the heat of the jacketwater entering the engine is above or below a predetermined operating temperature.

'7. A system for controlling the temperature of the jacket water and of the lubricating oil of an internal combustion engine, which comprises a heat exchanger through which lubricating oil from the engine is circulated, a jacket water cooler, means for circulating water from the engine through the heat exchanger and cooler, and

temperature-controlled means governed by the heat of the jacket water for by-passing jacket water around said cooler. 1

8. A system for controlling the temperature of the jacket water and that of the lubricating oil of an internal combustion engine, which includes a lubricating oil heater and a jacket water cooler,

means for simultaneously circulating jacket water from'the engine through said heater and said cooler and for returning the same to the engine, means for circulating lubricating oil from the engine through said heater and back to the engine, and means governed by the heat of the lubricating oil being circulated controlling the temperature of the jacket water leaving the enine.

- 9. A system for controlling the temperature of the jacket water and that of the lubricating oil of an internal combustion engine, which comprises an oil heater, a jacketwater cooler, means for circulating jacket water from the engine through the heater and the cooler to the engine, means for circulating jacket water from the cooler back simultaneously through both the coolerand the heater.

EDWARD F. CHANDLER. 

